In-place resurfacing of ponderous cylinders



DSC- 18, 1951 R. G. MINARIK ErAL 2,579,391

1N-PLACE REsuRFAcING oF PoNnERous CYLINDERS Filed June l5, 1946 The belt |c is trained around a pulley 35 on the extended end of shaft 36 of a tension roll 31, which tension roll, forl a. purpose which will .1

hereafter appear, is also mounted in a manner similar to the mounting of the roll 26,l sothat 1` the distance between the ends of -theroll 3,1v and flexible to permit the sliding adjustments heretofore referred to.

, The sizes of the pulleys on the., motor shaft and the roll shaft 25.and.roll shaft 36, and the speed of the motor are such that the peripheral `speed of the rolls 26 and 31 is equal and is about 2500 linear feet per minute. Around the rolls 26 `and 31, thereis trained an endless abrasive belt 38 of conventional type such as is frequently used in the woodworking industry. However, the particular type of abra-g sive employed is one which will .be most effective in the removal of the metal of which the drying cylinder is constructed. It will be found in general lmore satisfactory to use a relatively coarse abrasive for the initial or roughing opera. tion and then finish or polish the rough ground surface with another belt coated with anabra-f sive of Ysmaller particle size. In operation, the position of the roll 26 relative to the .cylinder l0 is so adjusted thatthe space between v the faces of rolls I0 and 26 lwill be slightly'less than .the thickness of the belt,.and hence the outer abrasive surface of thebelt 38 will engage the'surface of the cylinderfflll within the arc of contact between Ythe belt andthe form roll 26.` The spacing of. the .tension roll relative to the form roll is so adjusted that thetension of the belt is effective toA secure a driving effect from bothrof. the rolls 26 and 31. Y Obviously, it vis necessary to provide some ar-V rangement by which the `belt 38 may be caused to travel from one end of the roll 26 tothe other sothat all portions of the face of the Adriving cylinder l0 will receive `the same abrasive treatment. In order to insurefull abrasive treatment of the edges of the drying cylinder IIJ, the form roll 26 is .desirably at least as long as, or longer than, the drying cylinder to permit the edge of the belt to reach the edge of thecylinder before -the direction of traverse is reversed. With a belt about 12 inches to 18 inches wide, it is found convenient to :effect traverse of thebelt K38 at the rate .ofv about 6 inches per minute, so that, fora drying cylinder having a 12-foot face, the belt 38 will travel from one end of the cylinder tothe other in approximately `minutes. It Awill be understood that during the .time which is required to effect a complete surfacing operation on thecylinder l0, it will be necessary not only to make repeated traverses of the belt 38 along the cylinder, but it will be necessary from time to time to effect a micrometric movement of the ends of the shaft 25 towards the roll l0. In the case of a drying cylinder having a 12-foot V.faceand 12V `feet in diameter. acomplete rough:

, ofthe (Zylinder. the ends of the roll 26 may be respectively adjusted. The belts 15b and |5c are suiciently 4 grind operation can be made in about 6 hours. During this period, it may be necessary or advisable to replace or renew the belt 38 from time to time, but such belts are relatively inexpensive compared with the entire cost of the operation. These belts are found to be very uniform in thickness, aso that no ,difficulties are fordinarily Aencountered because offtvaryinglbelt thickness.

It is apparent that, due to the nature of the operation, the contour of the face of the cylinder I6 will be a reproduction, in reverse, of the conto'urV of the face of the form roll 26, that is to say, the high spots on the cylinder will be incrementally reduced until the profile of the cylinder face parallels the profile of the face of the formrol1i26 throughout the entire circumference Therefore, if it is desired to provide a crown (over-size central diameter) on the Vcylinder I0, the face of the form roll 26 should be inversely crowned, i. e. if it is desired that the drying cylinder l0 have in the middle of the face a finished diameter which is say-.02 inch greaterv than-at the ends, it is merely necessary to form the surface of the form roll 26 with an inverse crown of the same dimensions,:i.f,e. with a diameter in the middle of the face which is .02:inch less than the diameter at pointsvadjacent theends of roll l0.. v A f i l AVarious means may be employed for the purpose of effecting traversev of the belt 38along the rolls 26 and 31.V Any slow moving .traversing arrangement, automatic or otherwise, may :be employed in connection with a suitable beltshifting mechanism. However, inthe present instance we have found that it is convenient to effect the traverse of the belt by canting the axis of the roll 31 with respect to the axis ofthe form roll 26. 'I'his adjustment maybe ,made 'by -shifting one end of the roll 31 toward or away from the formvroll 26, according to the desired direc-,- tion of the traverse of the belt. For this purpose, the bearings which support'th'e shaft 36 are constructedv so as to Vbe movable initheir mountings in the manner provided for the feeding adjustment, previously described, Vof the form roll 26. Inv view of the fact that a` complete traverse of the belt from one end to the other of the roll requires about one-half hour, Ythe manual adjustment vof the bearing slide inthis mannerpresents no particular difficulty, Vespecially in `view of the fact that 'the operatoris naturally in attendance throughout the entire operation. Y Another method of effecting traverse of the abrasive belt is to employ an additional guide roll 39 for the abrasive belt 38 and located-between theform roll 26 and the `tension r'oll 3T. By inclining the axis of guide roll 39 relative to the direction of belt travel of the abrasive belt 38,l said vabrasive belt 38 will be caused to'travel laterally in accordance with the inclination ofthe guide roll axis.` Y I By inclining the axis of the form roll 0r of the cylinder being ground, so that 'the said axes do not lie in the same plane, while stilljkeeping' said axes substantially parallel with each' other, the contour of the nished ground cylinder can be madeumore concavecr less `convex,fi.' eiwithl less crown than would befrepres'ented by the re,- verse crown of the form roll. Therefore, bymthat expedient, a form roll having Aa relatively large inverse crown can be used to grind a cylinder so as to produce a positive crown which isfless than the inverse crown or concavity of the form We claim:

Apparatus for grinding the surface of a heavy cylinder comprising a substantially cylindrical form roll which is at least as long as said cylinder, means for rigidly and inflexibly supporting said form roll and the cylinder for rotation on substantially parallel axes, a tension roll, means for rotatably supporting said tension roll'on an axis substantially parallel with the axis of said form roll, means for rotating said cylinder, means for incrementally moving said form roll toward the cylinder, an endless belt trained around said rolls and having a width which is a minor fraction of the length of said form roll, means for positively rotating at least one of said rolls, said belt having an outer abrasive surface contacting the face of said cylinder in abradiner engagement within a zone overlying the arc of contact between said belt and the face of said form roll,

and means for inducing said belt to repeatedly H traverse the face of said form roll so as to operate upon the entire length of the face of said cylinder to thereby incrementally reduce any high spots on the face of said cylinder unti1 the profile of the face of the cylinder parallels the prole The following references are of record in the l RUDOLF G. li/IINARIK. ERIC N. ISAKSON.

REFERENCES CITED le of this patent:

UNITED STATES PATENTS Number Number Name Date Spencer Apr. 17, 1883 Totman Aug. 24, 1886 Driver Feb. 8, 1898 Linton Apr. 8, 1902 Richardson Aug. 7, 1923 Heintz Oct. 30, 1928 Olsen Nov. 5. 1940 FOREIGN PATENTS Country Date Great Britain 1903 

